'\" t
.\"     Title: pg_controldata
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.75.2 <http://docbook.sf.net/>
.\"      Date: 2011-12-01
.\"    Manual: PostgreSQL 9.1.2 Documentation
.\"    Source: PostgreSQL 9.1.2
.\"  Language: English
.\"
.TH "PG_CONTROLDATA" "1" "2011-12-01" "PostgreSQL 9.1.2" "PostgreSQL 9.1.2 Documentation"
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.SH "NAME"
pg_controldata \- display control information of a PostgreSQL database cluster
.\" pg_controldata
.SH "SYNOPSIS"
.HP \w'pg_controldata\ 'u
pg_controldata [\fIoption\fR] [\fIdatadir\fR]
.SH "DESCRIPTION"
.PP

pg_controldata
prints information initialized during
initdb, such as the catalog version\&. It also shows information about write\-ahead logging and checkpoint processing\&. This information is cluster\-wide, and not specific to any one database\&.
.PP
This utility can only be run by the user who initialized the cluster because it requires read access to the data directory\&. You can specify the data directory on the command line, or use the environment variable
\fBPGDATA\fR\&. This utility supports the options
\-V
and
\-\-version, which print the
pg_controldata
version and exit\&. It also supports options
\-?
and
\-\-help, which output the supported arguments\&.
.SH "ENVIRONMENT"
.PP
\fBPGDATA\fR
.RS 4
Default data directory location
.RE
